The invention relates to a cylinder in accordance with the preamble of claim 1.
A counter-pressure cylinder has become known from DE 30 33 230 C2, whose journal is held in end plates. In this case an actuating element acts on each of the free ends of the journals protruding out of the end plates for the metered introduction of pressure forces for the purpose of compensating the sagging of the cylinder.
U.S. Pat. No. 4,913,051 discloses a cylinder of a rotary printing press, wherein a jacket of the cylinder is seated by means of rolling bearings on a support. A distance in the radial direction between the jacket and the support at the ends is permanently fixed by means of the rolling bearings. Further rolling bearings with adjusting means for changing the distance between the jacket and the support are arranged between these rolling bearings.
The object of the invention is based on creating a cylinder.
In accordance with the invention, this object is attained by means of the characteristics of claim 1.
The advantages to be achieved by the present invention reside primarily in that an introduction of the placement force takes place via the shaft and the bearings arranged between the jacket and the shaft. Because of this, tube bending, which corresponds to the tendency of the cylinder to bend, already occurs when the cylinder is put down. The bending compensation takes place via the exterior bearings.
By arranging a bearing with an adjustment drive at the ends of the jacket, weakening because of the space requirements of the adjustment drive becomes necessary only in the area of the ends of the support, or jacket. In contrast to actuating drives located in the interior, this results in an improved flexural strength.
The interior and exterior bearings are placed within a common hydraulic fluid circuit, therefore later greasing of the bearings is not necessary. Further than that, a permanent fluid circulation between both ends of the counter-pressure cylinder leads to the removal of the heat from the rubber-coated cylinder jacket, which was generated by the flexing of the rubber blanket.
A shorter shaft distance and a shorter total length result because all bearing points are housed inside the tube jacket, an improved installation possibility is created because of this, also when retrofitting existing presses.
The design of the shaft seating makes assembly and disassembly easier in comparison with known embodiments.
An exemplary embodiment of the invention is represented in the drawings and will be described in greater detail in what follows.